Newswise — (St. Louis)- As the flowers and trees begin to bloom, millions of Americans will be reaching for over-the-counter allergy medications. One of the largest culprits in spring-time allergies is hay fever. Nearly 19 million American adults and 7 million children suffer from symptoms every year. Before taking that first antihistamine, Clark Kebodeaux, Pharm.D., BCACP, assistant professor of pharmacy practice at St. Louis College of Pharmacy has several pieces of advice.

First, talk with a pharmacist before taking any antihistamine, even if you took the same medication last year. Pharmacists are medication experts with the training to ensure patients receive the most benefit from their medicine.

“Antihistamines are very effective at reducing common allergy symptoms like runny noses, sneezing, itchy eyes and congestion,” Kebodeaux says. “However, like all medication, it can interact with other medications or supplements, which could change the effectiveness of the antihistamines or trigger side effects.”

The pharmacist will ask about diet and other medications. Certain antibiotics can increase the effects of antihistamines. Some antacids, taken too quickly after the antihistamine, can reduce the benefit patients receive from the allergy medication.

“Patients even need to watch out for that morning glass of fruit juice,” Kebodeaux says. “Orange juice can significantly reduce the effectiveness of one kind of once-a-day antihistamine. Patients should also avoid alcohol.”

What may appear to be allergy symptoms might be anything from bronchitis to the flu or a cold. There is even a chance it could be the first signs of asthma.

“In some cases, the pharmacist may not recommend any medication and instead suggest that the patient see their physician,” Kebodeaux says.

More information from Dr. Kebodeaux:• The biggest difference between all the antihistamines on the shelf is how often patients take the medicine and their side effects.“In general, these medications you see heavily advertised every spring and fall will make patients less drowsy,” Kebodeaux says. “However, every patient is different and less publicized formulations of medication may be more effective.”

• One of the most common side effects to antihistamines is a dry mouth. “Staying hydrated while taking these medications is extremely important,” Kebodeaux says. “Not only could the extra water help with the dry mouth, staying hydrated will help your body to maximize the effectiveness of the medication.”

• Not all antihistamines are the same.“The packaging may say it treats the same symptoms, but they may react very differently for patients with pre-existing conditions or when combined with other medications,” Kebodeaux says. “For some patients, especially the elderly, they may be more prone to medication side effects and there may be a better medication option.”

About St. Louis College of Pharmacy: Founded in 1864, St. Louis College of Pharmacy is the region’s only independent college of pharmacy. The College is the fourth oldest and 10th largest college of pharmacy in America. Founded by luminaries such as Henry Shaw, St. Louis College of Pharmacy has been partnering with other recognized leaders to care for the health of our region’s citizens for 150 years. Located in the heart of one of the world’s finest biomedical research and patient-care centers, the College provides innovative education, research, and career opportunities for students. The College is viewed by leaders of other premier academic and health care organizations as a critical component needed to deliver high quality patient-centered care. The curriculum integrates the liberal arts and sciences alongside introductory and advanced practice experiences where students can develop expertise and become leaders in the profession and their communities. Beginning in the fall of 2014, the curriculum will expand to three undergraduate years and four years of the professional program. Graduates will earn a Bachelor of Science degree after four years, and a Doctor of Pharmacy (Pharm.D.) at the completion of their studies. The College admits students directly from high school and accepts transfer students and graduates from other colleges and universities. More than 1,300 students are currently enrolled from 28 states and several countries, including Canada, China, Korea, Saudi Arabia, Slovenia, and Vietnam. College alumni practice throughout the nation and in 13 different countries, providing a strong network to assist students with their goals. Additional information is available at